Area Forecast Discussion
Issued by NWS Grand Junction, CO

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491
FXUS65 KGJT 220415
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
1015 PM MDT THU JUL 21 2016

.UPDATE...
Issued at 903 PM MDT Thu Jul 21 2016

Rainshowers and thunderstorms continue at this hour but their
coverage and intensity decreased once the sun started setting.
While some convection will continue overnight, the flash flood
threat has decreased substantially so the flash flood watch has
been allowed to expire. Will still need to keep an eye on CO145
from Placerville to Sawpit and Telluride due to recent mudslides
there. Also, the Piceance Basin reported some flash flooding
earlier this afternoon so will also need to keep an eye out there
as well.

&&

.SHORT TERM...(Tonight through Friday night)
Issued at 325 PM MDT Thu Jul 21 2016

The monsoonal doldrums are in place. That is deep moisture is in
place and the steering flow is light. The subtle disturbance that
is driving our weather today is a disturbance near Meeker this
afternoon that is threatening heavy slow-moving showers. Storm
motion is to the northeast at 5 mph but storms are showing a
tendency to back build thus increasing the possibility of
localized flooding. This threat will end before sunset with the
loss of surface heating. Isolated storms could continue overnight
favoring the north and east.

Friday thunderstorm coverage looks to favor the Colorado central
and southern mountains with weak sheared vorticity forecasted
there through the afternoon. Once again isolated nocturnal storms
continue overnight. Afternoon temperatures will rise a few degrees
above normal...near normal for morning lows.

.LONG TERM...(Saturday through Thursday)
Issued at 325 PM MDT Thu Jul 21 2016

By Saturday, the large scale pattern change begins. The Pacific
NW upper Low ejects through the northern Rockies while the
subtropical High also expands across the southern tier of states
into the SE Pacific. The flow across the north veers to dry west.
The latest forecasted afternoon winds do not reach critical fire
weather criteria. For the southern forecast area marginal moisture
lingers for isolated to scattered late-day storms favoring the
Abajo and San Juan Mountains.

Daytime temperatures will be 5-10 degrees above normal across the
north and central zones, 0-5 degrees above across the south.

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1015 PM MDT Thu Jul 21 2016

Isolated to scattered shower and thunderstorm activity will
continue until around 09Z, diminishing in intensity. Then a few
storms will continue to throughout the remainder of the night and
into the morning. After around 16Z showers and thunderstorms will
again begin to increase, initially over the mountains. Storms will
intensify after around 19Z, becoming widespread over the southern
and central mountains. Heavy rain will be possible with the
stronger storms and may produce brief MVFR conditions at KDRO,
KTEX, KMTJ, KASE AND KEGE during the afternoon and early evening.
Activity will diminish later in the evening.

&&

.GJT Watches/Warnings/Advisories...
CO...None.
UT...None.
&&

$$

UPDATE...TGR
SHORT TERM...Joe
LONG TERM...Joe
AVIATION...EH



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